The post illustrates an accurate solution to directly print MBOX files with attachments. It is just a 2 major step procedure that can be implemented without any technical guidance.

How to Use downloaded Gmail Archive MBOX file in Outlook 2019, 2016, 2013, 2010, 2007, 2003, 2002, etc. versions. Google Mail Takeout service allows you t ...

Download eml2mbox (link in Resources), then double-click the downloaded archive to open it and drag the "eml2mbox.rb" file to the directory containing the EML files you want to convert.

Have you checked with process viewer, if there is a dead process of your mail program still lingering around that needs killing? That may still have "first rights" on the mbox file.<BR>Otherwise ...